CVE-2026-64285
KVM: SEV: Pin source page for write when adding CPUID data for SNP guest
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Pin source page for write when adding CPUID data for SNP guest When populating a guest_memfd instance with the initial CPUID data for an SNP guest, acquire a writable pin on the source page as KVM will write back the "correct" CPUID information if the userspace provided data is rejected by trusted firmware. Because KVM writes to the source page using a kernel mapping, pinning for read could result in KVM clobbering read-only memory. Note, well-behaved VMMs are unlikely to be affected, as CPUID information is almost always dynamically generated by userspace, i.e. it's unlikely for the CPUID information to be backed by a read-only mapping. [sean: rewrite shortlog and changelog, tag for stable@]
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Linux kernel to the latest stable version.
- Ensure VMMs generate CPUID information dynamically.
- Verify memory mappings for CPUID data.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64285.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/dcdb476f5fc5701ec06c23efe3e3529f07ca391e | Patch |
| https://git.kernel.org/stable/c/f13e900599089b10113ceb36013423f0837c6792 | Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64285 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64285
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64285 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64285 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'dcdb476f5fc5701ec06c23efe3e3529f07ca391e', 'versionType': 'git'}, {'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'f13e900599089b10113ceb36013423f0837c6792', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'dcdb476f5fc5701ec06c23efe3e3529f07ca391e', 'versionType': 'git'}, {'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'f13e900599089b10113ceb36013423f0837c6792', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Aug. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.0 up to (excluding) 7.1.4 Added Reference Type kernel.org: https://git.kernel.org/stable/c/dcdb476f5fc5701ec06c23efe3e3529f07ca391e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f13e900599089b10113ceb36013423f0837c6792 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'dcdb476f5fc5701ec06c23efe3e3529f07ca391e', 'versionType': 'git'}, {'status': 'affected', 'version': '2a62345b30529e488beb6a1220577b3495933724', 'lessThan': 'f13e900599089b10113ceb36013423f0837c6792', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/sev.c', 'arch/x86/kvm/vmx/tdx.c', 'include/linux/kvm_host.h', 'virt/kvm/guest_memfd.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Pin source page for write when adding CPUID data for SNP guest When populating a guest_memfd instance with the initial CPUID data for an SNP guest, acquire a writable pin on the source page as KVM will write back the "correct" CPUID information if the userspace provided data is rejected by trusted firmware. Because KVM writes to the source page using a kernel mapping, pinning for read could result in KVM clobbering read-only memory. Note, well-behaved VMMs are unlikely to be affected, as CPUID information is almost always dynamically generated by userspace, i.e. it's unlikely for the CPUID information to be backed by a read-only mapping. [sean: rewrite shortlog and changelog, tag for stable@] Added Reference https://git.kernel.org/stable/c/dcdb476f5fc5701ec06c23efe3e3529f07ca391e Added Reference https://git.kernel.org/stable/c/f13e900599089b10113ceb36013423f0837c6792